Borrowed from Jewels of Clinical Medicine: Facebook

A 30-year-old woman with known congenital heart disease presented to our clinic with a 1-year history of fatigue, hemoptysis, and progressive exertional dyspnea. On examination, the toes had mild cyanosis and marked clubbing, but the finger

s had subtle clubbing only. She was noted to have a left parasternal heave, a palpable second heart sound, and a systolic ejection murmur audible in the pulmonic area. Contrast echocardiography showed right atrial and right ventricular dilatation, an elevated mean pulmonary-artery pressure of 68 mm Hg, and bidirectional flow through a patent ductus arteriosus. In Eisenmenger's syndrome, a long-standing systemic-to-pulmonary circulatory shunt results in pulmonary hypertension and eventual bidirectional or pulmonary-to-systemic shunting of blood. When Eisenmenger's syndrome occurs in concert with a patent ductus arteriosus, deoxygenated blood from the right ventricle is delivered to the aorta distal to the left subclavian artery. The upper extremities are thus spared the effects of the shunt, whereas the lower extremities are not, resulting in differential clubbing and cyanosis